Simon Halabi, one of London's richest tycoons, has had £1.15bn of debt called
in, which could result in the sale of some of the City's most prominent
office buildings.

The Syrian-born property entrepreneur has a portfolio that includes JP Morgan's Alban Gate offices and St Helen's, headquarters of Aviva, the insurer.

However, a revaluation of the assets in June saw their value fall to £929m, down from £1.8bn at their peak in 2006, causing a breach of covenants on a bonds secured against the properties.

Hatfield Philips was brought in to restructure the securitisation and after a meeting with bondholders on Wednesday, it was announced that the accelerated repayment of the finance would be sought.

In a statement to the Irish Stock Exchange, the bondholders said: "This has resulted in the cancellation of the facility and the borrowers being required to repay the loan together with accrued interest and all other sums payable under the credit agreement, and as such, these sums have become immediately due and payable."

Related Articles

His other assets include the Naval and Military Club on London's Piccadilly and Mentmore Towers, the former home of Baron Mayer de Rothschild.

The bonds make up a securitisation vehicle called White Tower 2006-3, and their complex nature means that it is unclear what the eventual outcome for stakeholders will be.

However, the sale of the properties to meet the repayment or the appointment of receivers are likely outcomes.

The property empire would be one of the largest to be broken up as a result of the downturn, which has seen values fall by 45pc over the past two years. The UK's largest property companies, including Land Securities, have been forced to call on shareholders to raise billions to bolster their balance sheets. However, although rents remain under pressure, there are signs that investors are returning to the market.